Pharmacokinetics of cannabidiol in a randomized crossover trial in senior horses

Shelley E. Turner, Heather K. Knych, Amanda A. Adams

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4 Scopus citations


OBJECTIVE To determine the pharmacokinetics, bioavailability, and pharmacological effects of cannabidiol (CBD) in senior horses. ANIMALS 8 university-owned senior horses. PROCEDURES In this randomized, crossover study, horses were assigned to receive either a single oral dose of 2 mg/kg CBD in oil or a single IV dose of 0.1 mg/kg CBD in DMSO between August 10 and September 4, 2020. Blood samples were collected before and then 0.5, 1, 4, 8, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, and 264 hours after CBD admin-istration. Serum biochemical analyses and CBCs were performed. Plasma concentrations of CBD and its metabolites were determined with the use of liquid chromatography-tandem mass spectrometry. RESULTS Concentrations of CBD and metabolites (7-COH CBD and 7-COOH CBD) were detected in all plasma samples up to 8 hours after dosing (oral and IV), with 7-COOH CBD being the most predominant metabolite. Pharmacokinetic results for CBD oral dosing at 2 mg/kg were mean ± SD half-life of 7.22 ± 2.86 hours, maximum concentration of 18.54 ± 9.80 ng/mL, and time to maximum concentration of 2.46 ± 1.62 hours. For both oral and IV administrations, 7-COOH CBD did not fall below the limit of quantification for the times reported. Oral bioavailability for CBD was 7.92%. There was no meaningful effect of CBD on results for CBC, serum biochemical analyses, or vital signs for any horse. CLINICAL RELEVANCE Pharmacokinetics and bioavailability of CBD in senior horses were determined, and there were no adverse effects of administering either the oral or IV dose of CBD evaluated.

Original languageEnglish
JournalAmerican Journal of Veterinary Research
Issue number9
StatePublished - Sep 2022

Bibliographical note

Funding Information:
Funded by AgTech Scientific Corp. The funder had no involvement in the study design, data collection, analysis, interpretation of the results, writing of this article, nor sub-mission of this article for publication. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors would like to thank the farm staff at the University of Kentucky’s C. Oran Little Farm (Versailles, KY) for their assistance in the daily care of the research horses and the laboratory team for their assistance with the sam-ple collection. Additional thanks to Dr. Heather Knych and her laboratory team at the K.L Maddy Equine Analytical Pharmacology Laboratory, UC Davis, for their analysis of the samples.

Publisher Copyright:
© 2022, American Veterinary Medical Association. All rights reserved.

ASJC Scopus subject areas

  • Veterinary (all)


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